Age no barrier to being productive in Theoretical Physics

Edward & Nappi are 2 Theoretical Physicists married to each other, talking about where advances are most likely to be made in their field (part 2 of 2 of the article). Note that Ed's wife is confident that they can both still contribute effectively, despite being 50+.
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He reckons the most influential insights in string theory will come from the younger generation, but Nappi isn't so sure. She cites a recent study showing that scientists in their 50s and 60s are at least as productive as those in their 30s, if not more so. "We are planning to get a lot more work done now that the children have moved out," she says. It's a fearsome prospect: Ed Witten might just be entering his prime.
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Be sure to also look at part 1 of the article, Inside the tangled world of string theory!